The man accused of fatally stabbing a woman in a luxury Downtown apartment building gym Friday morning told police he became angry and struck the woman with a knife before he ran, according to a probable cause affidavit released Monday.

Cody Weir, 25, Avon, said he knocked on the door of the second-floor gym at the Canal Apartments on 9th St. and Carina Rodriguez, 23, let him in shortly before 3 a.m.

What prompted the anger and outburst of violence? Police said there's no indication the pair knew one another. No additional motive is mentioned in the affidavit.

"I remember swinging at her, I remember getting really angry and going in there," said Weir, according to the affidavit. "l remember l was right by the drinking fountain, I remember I was trying to get a drink to calm myself down."

Weir said he had a knife in his hand, he hit her and then ran, the document says.

Weir told police officers he "really didn't remember anything" that morning but recalled going past the apartment building at 335 W. 9th St. a couple of times. He said he used to go to the gym with a friend who lived there and even still had a key fob for the building but didn't use it to get into the gym on Friday.

Weir said he remembered getting really angry and trying to calm himself down while Rodriguez continued to work out. Moments later he said he hit Rodriguez once with his daggerlike knife, the document says.

According to the affidavit, surveillance video of the gym showed Rodriguez falling down and a short struggle before Weir leaves. Rodriguez staggered around and tried to use an iPad until she eventually falls down again.

A pair of roommates living in the apartment later found her dead in a pool of blood.

An autopsy revealed a single stab wound to her right shoulder and neck. Her death was ruled a homicide. Weir is facing a preliminary charge of murder.

Hours later one of Weir's childhood friends reported Weir to the police after the friend's girlfriend said she thought Weir looked like the man in the video clip. The friend told police he had seen Weir that morning and he was wearing a similar hoodie and appeared to have blood on his work boots.

Weir was previously arrested in 2013 in Hendricks County on charges of holding a woman at gunpoint and raping her. The following year a jury found him not guilty on all charges and shortly thereafter returned a black 9 mm Beretta semiautomatic gun to him.

The death marked the 113th criminal homicide in Indianapolis this year. The city saw a record 149 criminal homicides in 2016.